JPH0835563A - Sealing device for reciprocating movement - Google Patents

Abstract

PURPOSE:To improve installation performance by facilitating the positioning in the press-fitting assembly by improving the shape of a seal body and to improve the slip-off preventing performance of the seal body from a housing. CONSTITUTION:A sealing device for reciprocating movement is equipped with a cylindrical bearing 4 fitted with an installation hole 3 formed on a housing 2, seal body 6 which consists of a rubber elastic body which makes sealing contact in a slidable manner with the outer periphery of a reciprocating movement shaft 5 which is installed at the end part of the bearing 4 and supported on the bearing 4, and a projection 10 is formed at the outer peripheral part of the seal body 6, and a projection 12 is nipped and fixed between the inner periphery of the installation hole 3 of the housing 12 and the bearing 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating sealing device for sealing a reciprocating shaft such as a piston rod of a hydraulic cylinder. In particular, the present invention relates to a reciprocating sealing device which is made of a rubber-like elastic body and which is used together with a bearing and has improved mountability and detachability.

[0002]

2. Description of the Related Art As a conventional reciprocating sealing device of this type, for example, one shown in FIG. 2 is known.
That is, the reciprocating sealing device is provided with the housing 100.
Cylindrical bearing 10 fitted into a mounting hole 101 provided in the
2 and a seal body 103, which is attached to the end of the bearing 102 and is a rubber-like elastic body alone.

The outer periphery of the seal body 103 is the housing 10
A lip 105 is fitted into the inner periphery of the mounting hole 101 of No. 0, and slidably sealingly contacts the outer periphery of the reciprocating shaft 104 supported by the bearing 102.

The mating surface between the seal body 103 and the bearing 102 is provided with a protrusion 106 protruding at the inner diameter side end of the bearing 102 in accordance with the shape of the base of the lip 105. Supports the lip 105 from behind. On the other hand, the outer diameter side end is a straight surface that is perpendicular to the axis.

[0005]

However, in the above-mentioned prior art, the seal body 103 is attached to the housing 100.
There is a problem that it is difficult to position the seal body 103 when it is press-fitted into the mounting hole 101, and the mounting is unstable and unstable. The reason is that the seal body 103
Since the seal is made of only a rubber-like elastic body, the seal body 103 is easily deformed during press fitting, and the housing 100
This is because the seal body 103 is simply fitted to the inner circumference of the mounting hole 101, so that the positioning cannot be performed.

There is also a problem that the seal body 103 may come off when the pressure on the mounting side of the seal body 103 becomes a negative pressure. That is, the bearing 102 has the stop ring 107, and the housing 100
Although the press-fitting and assembling position of the bearing 102 is fixed to the bearing 102, the seal body 103 is not integrated with the bearing 102 by baking, so that the seal body 103 is positioned between the outer diameter of the seal body 103 and the inner diameter of the housing 100. Even if the tightening margin is provided, when the mounting side of the seal body 103 (for example, the oil side to be sealed by the seal body 103) is negative pressure, or when the shaft reciprocates repeatedly, the arrow A in FIG. There is a possibility that the seal body 103 may come off in the direction.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The object of the present invention is to improve the shape of the seal body to facilitate positioning during press-fitting and assembly. In addition, the seal body is improved, and the seal body is prevented from coming off from the housing to improve the removal performance.

[0008]

In order to achieve the above object, according to the present invention, a cylindrical bearing fitted in a mounting hole provided in a housing and mounted at an end portion of the bearing. A reciprocating sealing device comprising a rubber-like elastic seal body slidably sealingly contacting the outer periphery of a reciprocating shaft supported by the bearing, wherein a protrusion is provided on an outer peripheral portion of the seal body. Is fixed by being sandwiched between the inner periphery of the mounting hole of the housing and the bearing.

On the inner circumference of the housing where the projection is sandwiched,
The present invention is characterized in that a taper portion is provided so as to be gradually reduced in diameter in the protruding direction of the projection.

[0010]

In the present invention, since the protrusion provided on the seal body is sandwiched between the inner periphery of the mounting hole of the housing and the bearing, the mounting position of the seal body is stable and the fixing force is large.

Since the fixing force is large, it becomes a resistance when the seal body comes off, and a function of preventing the seal body from coming off occurs.

Further, if a taper portion is provided on the inner circumference of the mounting hole of the housing, the mounting position is stabilized, and the effect of preventing removal is enhanced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments.

FIG. 1 shows a reciprocating sealing device according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes the entire reciprocating sealing device, which is roughly a mounting hole 3 provided in a housing 2.
A cylindrical bearing 4 fitted to the bearing 4, a rubber-like elastic seal body 6 slidably sealingly contacting the outer periphery of a reciprocating shaft 5 mounted on the end of the bearing 4 and supported by the bearing 4, Is equipped with.

The seal body 6 is an annular member formed of a single rubber-like elastic body, the outer periphery of which is fitted into the inner periphery of the mounting hole 3 of the housing 2, and the inner periphery of the lip 7 is in contact with the reciprocating shaft 5.
Is provided. A spring 8 is attached to the outer periphery of the lip 7 in order to supplement the tightening force of the lip 7 and to improve the followability of the lip 7 to the shake of the shaft.
Further, on the outer periphery of the seal body 6, an annular convex portion 9 is provided to obtain a tight margin with respect to the inner periphery of the housing 2 in order to seal the fitting portion with the inner periphery of the mounting hole 3 of the housing 2.

An annular protrusion 10 is provided on the outer peripheral portion of the end surface of the seal body 6 on the bearing 4 side, and the protrusion 10 is sandwiched and fixed between the inner periphery of the mounting hole 3 of the housing 2 and the bearing 4. .

The bearing 4 has a ring-shaped projecting portion 12 on the end surface which is a mating surface with the seal body 6, and first on the inner diameter side, the tapered surface 11 which is the base of the lip 7 of the seal body 6 is fitted. Is provided. This fits tightly to the taper portion 11 which is the base of the lip 7 of the seal body 6 and has a function of preventing the lip 7 from being turned upside down. Similarly, the protrusion 10 of the seal body 6 fits exactly on the outer peripheral side of the mating surface of the bearing 4, and the protrusion 10 is slightly expanded to the outside so as to be pressed against the inner periphery of the mounting hole 3 of the housing 2. Is provided.

A stop ring 14 for restricting axial movement of the bearing 4 is provided between the bearing 4 and the inner periphery of the mounting hole 3 of the housing 2.

The inner diameter of the mounting hole 3 of the housing 2 is not straight, and the inner diameter is large on the bearing 4 side and small on the seal body 6 side. However, the difference in diameter is small. The location where the diameter changes is the location of the protrusion 10 of the seal body 6, rather, it is near the root of the protrusion 10 from the center. In addition, the change in the inner diameter of the housing 2 does not change suddenly in steps, but the width is 3 to 4 m.
It changes in the taper part 15 of about m. The tapered portion 15 is chamfered.

According to the above-described embodiment, since the protrusion 10 provided on the seal body 6 is sandwiched between the inner circumference of the mounting hole 3 of the housing 2 and the bearing 4, the mounting position of the seal body 6 is eliminated and the seal body 6 is mounted. The position is stable and the fixing force is large.

Since the fixing force is large, it becomes a resistance when the seal body 6 comes off, and a function of preventing the seal body 6 from coming off occurs.

Further, if the tapered portion 15 is provided on the inner circumference of the mounting hole 3 of the housing 2, the mounting position is stabilized, and the effect of preventing slipping out is enhanced. In particular, the protrusion 10 of the seal body 6 tends to be slightly spread out by the ring-shaped recess 13 of the bearing 4, and the press-fitting margin of the protrusion 10 at the tapered portion 15 increases, so that the mounting is further stabilized. .

In this way, the projection 10 of the seal body 6 is still ring-shaped recessed portion of the bearing 4 even after the seal body 6 is mounted in the same manner as when the taper portion 15 functions as the press-fitting positioning when the seal body 6 is mounted. It is sandwiched between 13 and taper part 15,
The seal main body 6 serves as resistance when the seal main body 6 comes off in the direction of arrow A in the figure, and the function of preventing the seal body 6 from coming off in the direction A is enhanced.

[0025]

As described above, according to the present invention,
Since the protrusion provided on the seal body is sandwiched between the inner periphery of the housing mounting hole and the bearing, the mounting position of the seal body is more stable than simply fitting the seal body inside the inner mounting hole of the housing as in the past. However, the fixing force also increases.

Further, since the fixing force is large, it becomes a resistance when the seal body comes off, and it is possible to prevent the seal body from coming off.

Further, if a taper portion is provided on the inner periphery of the mounting hole of the housing in which the projection is sandwiched, the mounting position is further stabilized and the effect of preventing removal is enhanced.

[Brief description of drawings]

FIG. 1 (a) is a half sectional view of a reciprocating sealing device according to an embodiment of the present invention, and FIG. 1 (b) is a partially enlarged sectional view of a protrusion.

FIG. 2 is a half sectional view of a conventional reciprocating sealing device.

[Explanation of symbols]

 1 Reciprocating Sealing Device 2 Housing 3 Mounting Hole 4 Bearing 5 Reciprocating Shaft 6 Seal Body 7 Lip 8 Spring 9 Projection 10 Protrusion 11 Tapered Surface 12 Projection 13 Recess 14 Stop Ring 15 Tapered

Claims (2)

[Claims] 1. A cylindrical bearing fitted into a mounting hole provided in a housing and a reciprocating shaft mounted on an end of the bearing and supported by the bearing slidably and slidably contacting with the outer periphery thereof. In a reciprocating sealing device including a rubber elastic seal body, a protrusion is provided on an outer peripheral portion of the seal body, and the protrusion is sandwiched and fixed between an inner periphery of a mounting hole of the housing and a bearing. Reciprocating sealing device. 2. The inner circumference of the housing, in which the protrusion is sandwiched,
2. The reciprocating sealing device according to claim 1, further comprising a taper portion that is inclined so as to have a gradually smaller diameter in a protruding direction of the protrusion.